Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 60951 — Martinton, IL

ZIP code 60951 (Martinton, Iroquois County) is in USDA zone 5b: the coldest winter night averages −15 to −10 °F. The median last spring frost is April 24 and the first fall frost October 16.

Where ZIP 60951 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone5b−15 to −10 °F
Coldest night−26.1 to −23.3 °C
Last frostApr 24
First frostOct 16
2012 zone5b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 5b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Martinton, IL…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Martinton, IL

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 24median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 16median — 10% chance by Oct 1
Growing season174 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 12 and returns around October 26.

From the NOAA station Watseka 2 Nw, IL — 9 miles away, elevation 620 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 60951

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 13 – Mar 27
SpinachSow outdoors · Mar 13 – Apr 3
Broccoli, cabbageStart indoors · Feb 13 – Feb 27
Broccoli, cabbageTransplant · Apr 3 – Apr 17
Onion setsPlant outdoors · Mar 27 – Apr 10
PotatoesPlant outdoors · Apr 3 – Apr 17
LettuceSow outdoors · Mar 27 – Apr 10
Carrots, beetsSow outdoors · Apr 3 – Apr 17
TomatoesStart indoors · Feb 27 – Mar 13
TomatoesTransplant · May 1 – May 15
Peppers, eggplantStart indoors · Feb 13 – Feb 27
Peppers, eggplantTransplant · May 8 – May 22
BeansSow outdoors · May 1 – May 15
Sweet cornSow outdoors · May 1 – May 15
Cucumbers, squashSow outdoors · May 1 – May 15
Fall lettuce, spinachSow outdoors · Aug 21 – Sep 4
GarlicPlant cloves · Oct 2 – Nov 6
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 24) and first fall frost (Oct 16) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 60951 came on Mar 21 — 12 days earlier than the 1991–2020 average (Apr 2).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Soil in Martinton, IL

The soil mapped at the center of ZIP 60951 is Milford — silty clay loam, poorly drained.

TextureSilty clay loamholds water and nutrients; slow to drain and warm up
pH6.1slightly acidic; most vegetables like 6.0–7.0
DrainagePoorly drainedconsider raised beds
Organic matter5.25%high
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Milford silty clay loam, 0 to 2 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 60951; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Martinton, IL

Summer high85 °Faverage high, July
Winter low16 °Faverage low, January
Hot days16days a year at 90 °F or more
Freezing nights133nights a year at 32 °F or less
Growing degree days3,256base 50 °F — the season’s usable heat
Longest day15 h 07 mindaylight on June 21
Shortest day9 h 14 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation40.8 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°100°32 °FJanuary: average high 33 °F, low 16 °F 33°16° JanFebruary: average high 37 °F, low 18 °F 37°18° FebMarch: average high 50 °F, low 29 °F 50°29° MarApril: average high 62 °F, low 38 °F 62°38° AprMay: average high 74 °F, low 50 °F 74°50° MayJune: average high 82 °F, low 60 °F 82°60° JunJuly: average high 85 °F, low 63 °F 85°63° JulAugust: average high 83 °F, low 60 °F 83°60° AugSeptember: average high 79 °F, low 52 °F 79°52° SepOctober: average high 66 °F, low 41 °F 66°41° OctNovember: average high 51 °F, low 31 °F 51°31° NovDecember: average high 38 °F, low 21 °F 38°21° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.30 in precipitation 2.3 JanFebruary: 2.06 in precipitation 2.1 FebMarch: 2.63 in precipitation 2.6 MarApril: 3.75 in precipitation 3.8 AprMay: 4.44 in precipitation 4.4 MayJune: 4.97 in precipitation 5.0 JunJuly: 4.22 in precipitation 4.2 JulAugust: 3.99 in precipitation 4.0 AugSeptember: 4.07 in precipitation 4.1 SepOctober: 3.33 in precipitation 3.3 OctNovember: 2.82 in precipitation 2.8 NovDecember: 2.20 in precipitation 2.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Watseka 2 Nw, IL (9 mi away); precipitation: Ashkum 5.6 E, IL (6 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 5b.

609565b
Papineau, IL · 4 mi
609645b
Saint Anne, IL · 8 mi
609125b
Beaverville, IL · 8 mi
609315b
Donovan, IL · 8 mi
609705b
Watseka, IL · 9 mi
609455b
Iroquois, IL · 10 mi
609105b
Aroma Park, IL · 11 mi
609225b
Chebanse, IL · 11 mi

Illinois planting zones →

Questions about 60951

What planting zone is ZIP code 60951?

ZIP code 60951 (Martinton, IL) is in USDA hardiness zone 5b on the 2023 map: the coldest night of an average winter reaches −15 to −10 °F (−26.1 to −23.3 °C).

When is the last frost in Martinton, IL?

The median last spring frost (32 °F) near 60951 is April 24; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Watseka 2 Nw station.

When is the first frost in Martinton, IL?

The median first fall frost near 60951 is October 16, giving a median frost-free growing season of 174 days.

When should I plant tomatoes in 60951?

Start tomato seeds indoors around Feb 27 – Mar 13 and set transplants outside around May 1 – May 15, one to three weeks after the median last frost.

How much rain and snow does 60951 get?

About 40.8 inches of precipitation a year (NOAA 1991–2020 normals, Ashkum 5.6 E station).

How hot do summers get in Martinton, IL?

The average high peaks at 85 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 60951 have?

The USDA soil survey maps Milford at the center of ZIP 60951: silty clay loam, poorly drained, pH about 6.1 (slightly acidic).

Did spring come early in Martinton, IL in 2026?

Spring leaf-out near 60951 came on Mar 21 in 2026, 12 days earlier than the 1991–2020 average (Apr 2), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Martinton, IL?

Long-day onions: the longest day near 60951 is 15 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).